The function as an intermediate element between the drive device which exercises the force required for the movement and the load to be moved inevitably means that load acceptance hooks of the type in question must be capable of reliably transferring the static and dynamic forces which arise in the course of moving the load. Hooks which meet these requirements are usually manufactured by heat forming, in particular drop-forging, of a suitable steel. Such hooks are available, for example, under the designation JH-1 from Spanset AG, Oetwil am See, Switzerland, under the designation VIP-Cobra-Ösenhaken VCÖH, from RUD Kettenfabrik Rieger & Dietz GmbH & Co., Aalen, Germany or under the designation TWN 1835/1 6-XL from Thiele GmbH & Co. KG, Iserlohn, Germany. Forged hooks have a perceptibly higher load-bearing capacity than comparable components produced by casting or sintering.
In order to meet the constantly increasing loading requirements, despite the basically already high loading capacity of forged hooks, in the past materials have been developed which have been capable of sustaining ever increasing loads, the suitability of which for the manufacture of hooks of the kind in question has been increased still further thanks to suitable heat treatments.
At the same time, hooks have been developed the dimensions of which have been adapted to the demands which arise in practice. In particular due to the use of steel materials which are capable of high loading, subjected to additional suitable heat treatment, it has proved possible to avoid a disproportionate increase in weight as a result of the ever increasing dimensions of the hooks. It has nevertheless been shown that the hooks used in practice have in many cases become so heavy that they can only be handled with difficulty.